HONG KONG -- National pride appears to be preventing authorities here from using what may be their most potent weapon against speculators attacking the Hong Kong dollar.

That weapon is the threat to replace Hong Kong's currency with the U.S. dollar, thereby removing any target for speculators to aim at. Already, Argentina has raised the possibility of dropping its own currency in favor of the dollar. The suggestion, put forward recently by Argentine President Carlos Menem, came in the wake of rising concerns that Brazil's...